Interactions at the cell membrane and pathways of internalization of nano-sized materials for nanomedicine

• Valentina Francia,
• Daphne Montizaan and
• Anna Salvati

Beilstein J. Nanotechnol. 2020, 11, 338–353, doi:10.3762/bjnano.11.25

• endocytosis represents a complex cellular process with many molecules, feedback loops, and signalling cascades involved. The endocytosis field is still very active and constantly progressing [71][77][204]. Many processes and molecular details of these pathways are still unknown. For instance, in recent years

Implementation of data-cube pump–probe KPFM on organic solar cells

• Benjamin Grévin,
• Olivier Bardagot and
• Renaud Demadrille

Beilstein J. Nanotechnol. 2020, 11, 323–337, doi:10.3762/bjnano.11.24

• –acceptor blends with sub-ms time resolution [1]. Subsequent works have shown that sub-μs time resolution can be achieved by acquiring the full information on the cantilever oscillation, leading to the development of fast trEFM [2] and general-mode KPFM [3]. Contrary to feedback-free electrostatic methods

• [4][5], conventional KPFM relies on a closed feedback loop that compensates the tip–sample contact potential difference (CPD). It is thus inherently a rather “slow technique”. Kelvin controllers typically operate with time constants of a few to tens of ms. To implement time-resolved KPFM, a first

• are detected by demodulating the modulated component (ωmod) of the frequency-shift signal (Δf) with the LIA. The reference bias modulation voltage (Vmod, ωmod) and the compensation voltage generated by the KPFM feedback loop (VKPFM) are internally summed by the SPM unit. To generate the modulated bias

Nanosecond resistive switching in Ag/AgI/PtIr nanojunctions

• Botond Sánta,
• Dániel Molnár,
• Patrick Haiber,
• Agnes Gubicza,
• Edit Szilágyi,
• Zsolt Zolnai,
• András Halbritter and
• Miklós Csontos

Beilstein J. Nanotechnol. 2020, 11, 92–100, doi:10.3762/bjnano.11.9

• former. Preset contact resistance values of a few kiloohms were achieved by employing a current-controlled feedback loop. The first few periods of subsequent I(V) measurements were dominated by unstable, non-memristive curves, attributed to the initial formation of the metallic filament. They were

A review of demodulation techniques for multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2020, 11, 76–91, doi:10.3762/bjnano.11.8

• the cantilever according to the expression f−3dB = f0/2Q, where f0 is the fundamental resonance frequency. Assuming all other components in the z-axis feedback loop are also working at high speed [3], a low quality factor can demand a fast demodulator [12]. Multifrequency AFM (MF-AFM) is a major field

• techniques are not discussed in this article. Synchronous demodulation techniques employ a reference oscillator and can be categorized as either open-loop or closed-loop, depending on whether they use feedback to estimate parameters. Open-loop demodulators include the lock-in amplifier and coherent

• [52]. Fundamental to its operating principle, the Kalman filter utilizes a linear model of system dynamics and feedback of the state variables to update the Kalman gains, which controls the tracking bandwidth. When the time-varying system is discretized for t = kTs, where Ts is the sampling period

The effect of heat treatment on the morphology and mobility of Au nanoparticles

• Sven Oras,
• Sergei Vlassov,
• Simon Vigonski,
• Boris Polyakov,
• Mikk Antsov,
• Vahur Zadin,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2020, 11, 61–67, doi:10.3762/bjnano.11.6

• were heated to 100 °C to remove excess water. An image was first taken in the high-resolution QNM mode to find the Au particles. Then, the operation mode was switched to tapping mode. The oscillation amplitude was kept constant with a feedback loop on, and the power dissipated during tapping was

Atomic force acoustic microscopy reveals the influence of substrate stiffness and topography on cell behavior

• Yan Liu,
• Li Li,
• Xing Chen,
• Ying Wang,
• Meng-Nan Liu,
• Jin Yan,
• Liang Cao,
• Lu Wang and
• Zuo-Bin Wang

Beilstein J. Nanotechnol. 2019, 10, 2329–2337, doi:10.3762/bjnano.10.223

• surfaces [29][33]. When the probe sensor is in contact with the sample surface, the AFM cantilever directly reflects the vibrations. By modulating the drive frequency and the excitation amplitude used for AFAM imaging, the cantilever is set to adopt to the feedback signal. Finally, by analyzing the

Nitrogen-vacancy centers in diamond for nanoscale magnetic resonance imaging applications

• Alberto Boretti,
• Lorenzo Rosa,
• Jonathan Blackledge and
• Stefania Castelletto

Beilstein J. Nanotechnol. 2019, 10, 2128–2151, doi:10.3762/bjnano.10.207

Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

• Dominik Wrana,
• Karol Cieślik,
• Wojciech Belza,
• Christian Rodenbücher,
• Krzysztof Szot and
• Franciszek Krok

Beilstein J. Nanotechnol. 2019, 10, 1596–1607, doi:10.3762/bjnano.10.155

• /AFM system, where KPFM, LC-AFM and STM measurements were performed. KPFM, operating in FM mode, was used with a single-pass method, with three feedback loops maintaining the oscillation amplitude, phase and frequency shift [56]. The real oscillation amplitude was in the range of 10 nm. In order to

• forced to oscillate at higher harmonics, then the tip was retracted tens of nanometers from the surface, all feedback loops were turned down and a contact mode AFM scan was performed when approached with a single loop maintaining a deflection set point of 10–30 mV. The high conductivity of both TiO and

Development of a new hybrid approach combining AFM and SEM for the nanoparticle dimensional metrology

• Loïc Crouzier,
• Alexandra Delvallée,
• Sébastien Ducourtieux,
• Laurent Devoille,
• Guillaume Noircler,
• Christian Ulysse,
• Olivier Taché,
• Elodie Barruet,
• Christophe Tromas and
• Nicolas Feltin

Beilstein J. Nanotechnol. 2019, 10, 1523–1536, doi:10.3762/bjnano.10.150

• . In contact mode, the interaction force is kept constant during the scanning thanks to a feedback loop that controls the tip–sample distance. This mode is not really suitable for NP imaging because the NPs might be displaced by the tip over the sample. To avoid this effect, the intermittent contact

Kelvin probe force microscopy of the nanoscale electrical surface potential barrier of metal/semiconductor interfaces in ambient atmosphere

• Petr Knotek,
• Tomáš Plecháček,
• Jan Smolík,
• Petr Kutálek,
• Filip Dvořák,
• Milan Vlček,
• Jiří Navrátil and
• Čestmír Drašar

Beilstein J. Nanotechnol. 2019, 10, 1401–1411, doi:10.3762/bjnano.10.138

• potential difference) measurement was achieved by the modulation of the VAC at a frequency higher than the bandwidth of the topography feedback system. The topography was measured by the oscillation at the first resonance frequency of the AFM tip, and VCPD was measured by the amplitude of the oscillation at

Molecular attachment to a microscope tip: inelastic tunneling, Kondo screening, and thermopower

• Rouzhaji Tuerhong,
• Mauro Boero and
• Jean-Pierre Bucher

Beilstein J. Nanotechnol. 2019, 10, 1243–1250, doi:10.3762/bjnano.10.124

• step-by-step temperature increase, the feedback loop was “on” (0.2 nA, −0.3V) to prevent accidental loss of the MnPc molecular junction. As soon as the stable sample temperature was reached, the feedback loop was opened (0.1 nA, −0.3 V) and the dI/dV spectra were acquired at the stabilized sample

• surprising since is too small to produce any smearing of the Kondo resonance [36]. The Seebeck coefficient S can be calculated from the dI/dV data as a function of the temperature, obtained at constant height with an open feedback loop [37]: where σ(V) is the differential conductance and Σ(V) is its

• vertically for clarity. The feedback loop has been opened at 0.1 nA, −0.30 V. (c) Maximum conductance of the zero-bias peak as a function of the sample temperature Ts . (d) Conductance step at positive bias as a function of the sample temperature Ts. (e) Close-up of the dI/dV spectra showing the zero-bias

Imaging the surface potential at the steps on the rutile TiO₂(110) surface by Kelvin probe force microscopy

• Masato Miyazaki,
• Huan Fei Wen,
• Quanzhen Zhang,
• Yuuki Adachi,
• Jan Brndiar,
• Ivan Štich,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2019, 10, 1228–1236, doi:10.3762/bjnano.10.122

• about 70 mV, which is consistent with a previous study, in which surfaces with a high step density were found to have a lower work function than surfaces with a low step density [28]. The drop in CPD at the steps is not due to a feedback error since the forward and backward curves of the topography and

Review of time-resolved non-contact electrostatic force microscopy techniques with applications to ionic transport measurements

• Aaron Mascaro,
• Yoichi Miyahara,
• Tyler Enright,
• Omur E. Dagdeviren and
• Peter Grütter

Beilstein J. Nanotechnol. 2019, 10, 617–633, doi:10.3762/bjnano.10.62

• faster than the KPFM feedback loop can track [36]. In this measurement mode, the tip–sample coupling is in an ‘always-on’ state and the time resolution is achieved by modulating the length of time the system is allowed to decay (i.e., the pulse-off time). The minimum time resolution is no longer limited

• To demonstrate the time resolution of this technique a validation measurement was performed using a cantilever with a low resonance frequency (16.7 kHz) and a conducting tip over a gold sample. The tip was retracted a short distance (ca. 20 nm) with the z-feedback turned off and a train of

• measurement was repeated 20 times with the z-feedback turned on and then back off between each measurement to minimize drift. Each pulse had the form V(t) = V0 + ΔV(1 − exp[−t/τ)] during the pulse-on period and V(t) = V0 during the pulse-off period with a duty cycle of 20%. To fit the data, the integral in

Intuitive human interface to a scanning tunnelling microscope: observation of parity oscillations for a single atomic chain

• Sumit Tewari,
• Jacob Bakermans,
• Christian Wagner,
• Federica Galli and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2019, 10, 337–348, doi:10.3762/bjnano.10.33

• to the motion control system that provides a continuous visual feedback to the operator during atomic manipulation. This allows the operator to become a part of the experiment and to make any adaptable tip trajectory that could be useful for atomic manipulation in three dimensions. The strength of

• and combined it with a molecular dynamics (MD) simulator that simulates in real-time the manipulation process going on in the STM. The MD simulation not only provides information about the atomic scale structure of the junction, but also serves as a visual feedback to the operator in real-time who can

• process and can moreover be used for 3D manipulation. Previously, for better control of atomic manipulations, an audible feedback has been used [7]. In this, the tunnel-current signal is amplified and put on headphones, so that one hears a “doink” when the atom hops from one position to the next. This is

Apparent tunneling barrier height and local work function of atomic arrays

• Neda Noei,
• Alexander Weismann and
• Richard Berndt

Beilstein J. Nanotechnol. 2018, 9, 3048–3052, doi:10.3762/bjnano.9.283

• of the vertical tip excursion Δz the feedback loop of the STM was disabled at a sample voltage of V = 20 mV and a current of I = 200 pA. The tip was then brought closer to the structure under investigation at a rate of 1.7 nm/s while recording I. Figure 2 shows typical results from a clean (111

Investigation of CVD graphene as-grown on Cu foil using simultaneous scanning tunneling/atomic force microscopy

• Majid Fazeli Jadidi,
• Umut Kamber,
• Oğuzhan Gürlü and
• H. Özgür Özer

Beilstein J. Nanotechnol. 2018, 9, 2953–2959, doi:10.3762/bjnano.9.274

• the entire cycle. Consequently, while the constant tunnel current is used as feedback loop, the use of very small oscillation amplitudes ensures simultaneous STM/AFM operation as close as possible to the actual STM mode [30][33]. The combination of these two techniques attracts great interest for

In situ characterization of nanoscale contaminations adsorbed in air using atomic force microscopy

• Jesús S. Lacasa,
• Lisa Almonte and
• Jaime Colchero

Beilstein J. Nanotechnol. 2018, 9, 2925–2935, doi:10.3762/bjnano.9.271

• thus of type “uncleaned-new”, which is “almost clean”, as discussed below in more detail. Figure 2 shows the topography (a), the error signal of the feedback (frequency shift, (b)), the electrostatic capacity signal (EAFM2ν, see Experimental section, (c)) as well as the contact potential (e), which are

• . 2 kHz), which maintained the cantilever at resonance. Images and spectroscopy were acquired using the frequency as signal for the feedback channel (frequency-modulation dynamic mode; FM-DAFM [49]) at small oscillation, which generally implies non-contact operation (so-called attractive regime), for

• technique is used: the signal EAFMν is nullified with an auxiliary feedback system by adjusting the tip voltage UDC, then the voltage applied to the tip is precisely the contact potential (UDC = UCP). Frequency detection gives higher spatial resolution than force-detection electrostatic AFM, in addition, it

Charged particle single nanometre manufacturing

• Philip D. Prewett,
• Cornelis W. Hagen,
• Claudia Lenk,
• Steve Lenk,
• Marcus Kaestner,
• Tzvetan Ivanov,
• Ahmad Ahmad,
• Ivo W. Rangelow,
• Xiaoqing Shi,
• Stuart A. Boden,
• Alex P. G. Robinson,
• Dongxu Yang,
• Sangeetha Hari,
• Marijke Scotuzzi and
• Ejaz Huq

Beilstein J. Nanotechnol. 2018, 9, 2855–2882, doi:10.3762/bjnano.9.266

• in turn depends on the distance between tip and sample. The hybrid STM/AFM system from Quate et al. [145] uses two simultaneously operating feedback loops: one to keep the tip–sample distance constant by measuring the cantilever deflection and adjusting the z-position of the scanner, and the second

• -point. Since the oscillation amplitude depends on the force between tip and sample, its variation is a direct indicator for the topography and material properties of the sample. Tools that combine both feedback loops, i.e., current and force, are

Low cost tips for tip-enhanced Raman spectroscopy fabricated by two-step electrochemical etching of 125 µm diameter gold wires

• Antonino Foti,
• Francesco Barreca,
• Enza Fazio,
• Cristiano D’Andrea,
• Paolo Matteini,
• Onofrio Maria Maragò and
• Pietro Giuseppe Gucciardi

Beilstein J. Nanotechnol. 2018, 9, 2718–2729, doi:10.3762/bjnano.9.254

• removed from the near-field region of the sample, just excluding the feedback loop of the STM system. Vibrational bands of all molecules agree with the literature [60][61][62][63]. We finally apply our tips to obtain TERS spectra from the N-terminal domain of the Escherichia coli protein HypF (HypF-N

• oligomers when the STM feedback loop is on (red line) and when it is off (black line). Experimental conditions: λexc = 638 nm, P = 0.11 mW, t = 10 s. (a) STM image of Au(111) terraces on which R6G 10−4 M is adsorbed (∆V = 0.05 V – tip positive, current set point is 80 pA). The gray line indicates the zone

Nanoscale characterization of the temporary adhesive of the sea urchin Paracentrotus lividus

• Ana S. Viana and
• Romana Santos

Beilstein J. Nanotechnol. 2018, 9, 2277–2286, doi:10.3762/bjnano.9.212

• /MULTI/00612/2013, UID/MAR/04292/2013). Dissemination of results was supported by COST Action CA15216. The authors wish to acknowledge Guilherme Santos for his help in sea urchin field collection and three anonymous reviewers for their useful and constructive feedback on the manuscript.

Dumbbell gold nanoparticle dimer antennas with advanced optical properties

• Janning F. Herrmann and
• Christiane Höppener

Beilstein J. Nanotechnol. 2018, 9, 2188–2197, doi:10.3762/bjnano.9.205

• maintained with sub-nanometer accuracy to 2–4 nm by means of a force feedback loop regulating on the frequency shift of the force sensor, which is excited at its resonance frequency. The fluorescence emission rate as a function of the antenna–sample distance is recorded with the feedback loop switched off

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

A scanning probe microscopy study of nanostructured TiO₂/poly(3-hexylthiophene) hybrid heterojunctions for photovoltaic applications

• Laurie Letertre,
• Roland Roche,
• Olivier Douhéret,
• Hailu G. Kassa,
• Denis Mariolle,
• Nicolas Chevalier,
• Łukasz Borowik,
• Philippe Dumas,
• Benjamin Grévin,
• Roberto Lazzaroni and
• Philippe Leclère

Beilstein J. Nanotechnol. 2018, 9, 2087–2096, doi:10.3762/bjnano.9.197

• configuration considering no feedback control (right part) and feedback control (left part). The blue (orange) lines correspond to the situation in the dark (under illumination). eΔV (green color) represents the bond dipole in the dark, while eΔVlight (orange color) represents the photovoltage under

The structural and chemical basis of temporary adhesion in the sea star Asterina gibbosa

• Birgit Lengerer,
• Marie Bonneel,
• Mathilde Lefevre,
• Elise Hennebert,
• Philippe Leclère,
• Emmanuel Gosselin,
• Peter Ladurner and
• Patrick Flammang

Beilstein J. Nanotechnol. 2018, 9, 2071–2086, doi:10.3762/bjnano.9.196

• (Bruker Nano Inc., Santa Barbara, CA) using AFM in tapping mode. Tapping mode AFM was performed in amplitude modulation mode. The height of the cantilever position is constantly adjusted (via a feedback loop) to keep constant the ratio of the tip vibrational amplitude in contact with the sample surface to

Electromigrated electrical optical antennas for transducing electrons and photons at the nanoscale

• Arindam Dasgupta,
• Mickaël Buret,
• Nicolas Cazier,
• Marie-Maxime Mennemanteuil,
• Reinaldo Chacon,
• Kamal Hammani,
• Jean-Claude Weeber,
• Juan Arocas,
• Laurent Markey,
• Gérard Colas des Francs,
• Alexander Uskov,
• Igor Smetanin and
• Alexandre Bouhelier

Beilstein J. Nanotechnol. 2018, 9, 1964–1976, doi:10.3762/bjnano.9.187

• different strategies available from the literature ranging from the simple ramping of an applied voltage until breakdown to approaches relying on feedback mechanisms [34]. We finally settled on a method where the applied bias is manually adjusted to control the time evolution of the conductance of the